function http(params) {
    var http = new XMLHttpRequest();
    var par = ""
    if (params.hasOwnProperty("data")) {
        for (const key in params.data) {
            par+=`&${key}=${params.data[key]}`
        }
        params.url = params.url + par.replace("&", "?")
    }
    http.open(params.method, params.url);
    http.send();
    http.onreadystatechange = function () {
        if (http.readyState == 4 ) { 
            if (http.status == 200) { 
                var res = JSON.parse(http.responseText);
                if (res.error_code == 0) {
                    params.success(res)
                } else {
                    params.error(res)
                }
            } else {
              alert("网络不好")
            }
           
        } 
    }
}